1. Field of the Invention
The present invention is related to a gas spring which is incorporated into a suspension fork for two wheel vehicles.
2. Description of the Prior Art
Gas springs are known art. The following 30 patents and published patent applications are the closest prior art references which are related to the present invention.
1. U.S. Pat. No. 3,070,363 issued to John T. Ellis, Jr. on Dec. 25, 1962 for “Shock Absorber” (hereafter the “Ellis Patent”);
2. U.S. Pat. No. 3,344,894 issued to Grant F. Kenworthy on Oct. 3, 1967 for “Adjustable Hydraulic Shock Absorber” (hereafter the “Kenworthy Patent”);
3. U.S. Pat. No. 3,731,770 issued to Glyn A. Bindon and assigned to Ace Controls, Inc. on May 8, 1973 for “Adjustable Shock Absorber” (hereafter the “Bindon Patent”);
4. U.S. Pat. No. 3,990,548 issued to Willard J. Schupner and assigned to Efdyn Corporation on Nov. 9, 1976 for “Adjustable Hydraulic Dashpot” (hereafter the “548 Schupner Patent”);
5. U.S. Pat. No. 4,057,236 issued to Ransom J. Hennells on Nov. 8, 1977 for “Energy Absorber” (hereafter the “Hennells Patent”);
6. U.S. Pat. No. 4,071,122 issued to Willard J. Schupner and assigned to Efdyn Corporation on Jan. 31, 1978 for “Adjustable Shock Absorber” (hereafter the “122 Schupner Patent”);
7. U.S. Pat. No. 4,085,832 issued to Donald Raymond Gaines et al. and assigned to Gulf & Western Manufacturing Company on Apr. 25, 1978 for “Multi-Chambered Foam Energy Absorber” (hereafter the “Gaines Patent”);
8. U.S. Pat. No. 4,690,255 issued to Robert J. Heideman and assigned to Enertrols, Inc. on Sep. 1, 1987 for “Compact Shock Absorber” (hereafter the “255 Heideman Patent”);
9. U.S. Pat. No. 4,702,355 issued to Robert J. Heideman and assigned to Enertrols, Inc. on Oct. 27, 1987 for “Shock Absorber With Hole-On-Groove Configuration And With Adjusting Device” (hereafter the “355 Heideman Patent”);
10. U.S. Pat. No. 5,050,712 issued to Robert J. Heideman and assigned to Enertrols, Inc. on Sep. 24, 1991 for “Shock Absorber” (hereafter the “712 Heideman Patent”);
11. U.S. Pat. No. 5,720,369 issued to Richard P. Thorn on Feb. 24, 1998 for “Adjustable, Lockable Devices” (hereafter the “Thorn Patent”);
12. U.S. Design Pat. No. D457,300 issued to Donald Alan Kesinger on May 21, 2002 for “Shock Absorbing Post Assembly For Crutch And Bicycle Seat” (hereafter the “Kesigner Patent”);
13. U.S. Pat. No. 6,609,682 issued to Burl A. Rogers on Aug. 26, 2003 for “Airplane Landing Gear Suspension And Shock-Absorbing Device” (hereafter the “Rogers Patent”);
14. U.S. Pat. No. 6,981,578 issued to Troy Leiphart et al. on Jan. 3, 2006 for “Non-Pressurized Monotube Shock Absorber” (hereafter the “Leiphart Patent”);
15. European Patent No. 00250189 issued to Franz-Josef Wolf and assigned to WOCO Industrietechnik GmbH on Dec. 27, 2000 for “Air Damper” (hereafter the “Wolf European Patent”);
16. International Patent Application No. WO 01/01012 issued to Franz-Josef Wolf on Jan. 2, 2001 for “Air Shock Absorber” (hereafter the “Wolf International Patent Application”).
17. U.S. Pat. No. 2,934,332 issued to Jean Mercier on Apr. 26, 1960 for “Shock Absorber” (hereafter the “Mercier Patent”);
18. U.S. Pat. No. 4,782,898 issued to Scott L. Wellington et al. and assigned to Shell Oil Company on Nov. 8, 1988 for “Determining Residual Oil Saturation Using Carbon 14 Labeled Carbon Dioxide” (hereafter the “Wellington Patent”);
19. U.S. Pat. No. 5,538,276 issued to Jay K. Tullis on Jul. 23, 1996 for “Tunable Air Spring” (hereafter the “Tullis Patent”);
20. U.S. Pat. No. 5,775,677 issued to Arlo C. Englund on Jul. 7, 1998 for “Air Or Gas Sprung And Dampened Shock Absorber” (hereafter the “Englund Patent”);
21. U.S. Pat. No. 6,095,541 issued to Paul H. Turner et al. and assigned to RockShox, Inc. on Aug. 1, 2000 for “Adjustable Gas Spring Suspension System” (hereafter the “541 Turner Patent”);
22. U.S. Pat. No. 6,105,988 issued to Paul H. Turner et al. and assigned to RockShox, Inc. on Aug. 22, 2000 for “Adjustable Suspension System Having Positive And Negative Air Springs” (hereafter the “988 Turner Patent”);
23. U.S. Pat. No. 6,135,434 issued to John Marking and assigned to Fox Factory, Inc. on Oct. 24, 2000 for “Shock Absorber With Positive And Negative Gas Spring Chambers” (hereafter the “434 Marking Patent”);
24. U.S. Pat. No. 6,296,092 issued to John Marking et al. and assigned to Fox Factory, Inc. on Oct. 2, 2001 for “Position-Sensitive Shock Absorber” (hereafter the “092 Marking Patent”);
25. U.S. Pat. No. 6,311,962 issued to John Marking and assigned to Fox Factory, Inc. on Nov. 6, 2001 for “Shock Absorber With External Air Cylinder Spring” (hereafter the “962 Marking Patent”);
26. U.S. Pat. No. 6,415,895 issued to John Marking et al. and assigned to Fox Factory, Inc. on Jul. 9, 2002 for “Position-Sensitive Shock Absorber” (hereafter the “895 Marking Patent”);
27. U.S. Pat. No. 6,609,682 issued to Burl A. Rogers on Aug. 26, 2003 for “Airplane Landing Gear Suspension And Shock-Absorbing Device” (hereafter the “Rogers Patent”);
28. U.S. Published Patent Application No. 2003/0234144 issued to Robert C. Fox on Dec. 25, 2003 for “On-The-Fly Adjustable Air Spring” (hereafter the “Fox Published Patent Application”);
29. U.S. Published Patent Application No. 2004/0145101 issued to Steven J. Olds on Jul. 29, 2004 for “Coil And Air Suspension System” (hereafter the “Olds Published Patent Application”);
30. U.S. Pat. No. 6,938,887 issued to Martin Achenbach and assigned to DT Swiss Inc. on Sep. 6, 2005 for “Suspension System For Bicycles” (hereafter the “Achenbach Patent”).
The Ellis Patent discloses a conventional shock absorber with a piston and hydraulic fluid contained therein. The innovation is that the space between the perforated tube and the casting is filled with a tubular filler which fills the entire space at low pressure. It is compressed when it is under high pressure.
The Kenworthy Patent discloses an adjustable hydraulic shock absorber. The innovation is the inclusion of a closed cell cellular rubber accumulator which is provided near the bottom of the hydraulic reservoir.
The Bindon Patent discloses an adjustable hydraulic shock absorber having a shock receiving piston means telescopingly mounted over an axially disposed fluid metering tube means.
The 548 Schupner Patent discloses an adjustable hydraulic dashpot, which includes a cellular material 104 which is fabricated out of rubber or a comparable material which is disposed in the chamber 40 between the pressure collar tube portion 48 and the front end of the metering sleeve 60.
The Hennells Patent is an energy absorber. This patent discloses an adjustable energy absorber including a housing having a ram slidably extending therefrom. A first control sleeve divides the housing into a pair of fluid chambers, which sleeve has an axially extending row of openings to provide communication between the two chambers.
The 122 Schupner Patent discloses an adjustable shock absorber, which discloses a pad of resilient cellular material which is located in a reservoir.
The Gaines Patent is a multi-chambered foam energy absorber, wherein the energy absorption is derived from a multiplicity of aligned foam plastic materials.
The 255 Heideman Patent is a compact shock absorber, which includes an inner tube 10, a piston assembly 12, an outer tube 14 and a bearing member 16. The patent discloses that as part of outer tube 14 an annular accumulator chamber 28 is positioned in which a split annular accumulator pad 30 is positioned.
The 355 Heideman Patent is a shock absorber. It includes that a pad 60 is formed of cellular rubber which may be filled with nitrogen to give it a high degree of resilience and includes a slot 62 providing clearance for the adjuster mechanism and metering orifices.
The 712 Heideman Patent discloses an accumulator pad 60 which substantially fills the entire volume 58 and is secured against rotation therein by means of retainer pins 144 which extend through the cellular rubber which may be filled with nitrogen provided with a high degree of resilience.
The Thorn Patent discloses an adjustable locking device which as shown in the Figures is used primarily as the base for a chair which can be moved up and down and absorbs shock as the person sits on the chair and moves it.
The Kesinger Patent is a design patent which is described as a shock absorber and post assembly for crutch and bicycle seats.
The Rogers Patent deals with an airplane landing gear suspension, which includes a shock absorber that uses polyurethane cylinders, discs or a combination of discs and cylinders.
The Leiphart Patent discloses a non-pressurized monotube shock absorber. It utilizes a mechanically fixed base valve to regulate oil flow between the compression and the compression compensation chambers, and a compressible bladder in the compensation chamber to allow compensation, which together eliminate the need for pressurized gas and a floating piston which is in most conventional monotube shock absorbers.
The Wolfe European Patent is in German. From the English abstract it discusses a pneumatic shock absorber especially for car engines which comprises two parallel plates connected by a flexible membrane with an enclosed pneumatic dampening and resonance shape and a bore and at least one plate being connected to the chamber.
The Wolfe International Patent Application discloses an air shock absorber which includes two damping plates which are made of foam material similar to the previously discussed Wolfe Patent.
The Mercer Patent discloses a shock absorber, including resilient means within the chamber of the shock absorber.
The Wellington Patent deals with a process for determining oil saturation using carbon 14 labeled carbon dioxide.
The Tullis Patent discloses a tunable air spring and shock absorber that comprises a cylinder, a piston rod extending out of the cylinder through a lower end thereof, and rod guide provided on the lower end of the cylinder for guiding the piston rod, a seal mounted on the rod guide and piston containing valving components to deliver desired force-velocity characteristics for rebound and compression mounted on the piston rod.
The Englund Patent is an air or gas sprung and dampened shock absorber. Specifically, Claim 1 reads as follows: “A gas sprung and pressure dampened shock absorber utilizing compressed gas for dampening comprising; a cylinder having a closed end and an open end forming a compression chamber; a shaft having a closed end and an open end; said open end of said shaft being reciprocally received within said cylinder through said open end of said cylinder for contracting and expanding said compression chamber during compression and rebound strokes of the shock absorber; a piston having a closed end and an open end; said open end of said shaft being reciprocally received within said cylinder through said open end of said cylinder for contracting and expanding said compression chamber during compression and rebound strokes of the shock absorber; a negative gas spring chamber formed between an outer surface of said shaft and said inner surface of said cylinder; said negative gas spring chamber expanding and contracting inversely relative to said compression chamber; wherein said negative gas spring chamber is adapted to communicate with at least said rebound chamber during only a portion of the compression and rebound strokes of the shock absorber and is closed relative to the atmosphere.”
The 541 Turner Patent is an adjustable gas spring suspension system which has a negative pre-load gas adjustment system.
The 988 Turner Patent discloses an adjustable suspension system having positive and negative springs. However, the springs are either gas springs or air springs.
The 434 Marking Patent is a shock absorber with positive and negative gas spring chambers. It discloses damping cylinder 14 which preferably includes a floating piston 44. Floating piston 44 divides interior 21 of dampening cylinder 14 into a dampening fluid chamber 46, housing vented piston 32 and a gas chamber 48. Gas chamber 48 is sealable and is filled with a gas that acts as a spring, resisting compression by piston 44. Fluid chamber 46 is filled with a damping fluid, typically oil, thus damping the extension and collapse of the shock absorber.
The 092 Marking Patent is a position-sensitive shock absorber which talks about having a shock absorber. It also talks about having a damping means which includes a bypass channel for allowing the flow of fluid to go from one area to another. Claim 1 reads as follows: “A position-sensitive shock absorber comprising: a cylinder having an interior, first and second ends and defining an axis; a piston movably mounted within the cylinder for movement between the first and second ends; first and second bypass openings into the cylinder interior at first and second axially spaced-apart positions; a bypass channel fluidly coupling the first and second bypass openings; and a flow valve along the bypass channel permitting fluid flow from the first opening to the second opening and restricting fluid flow from the second opening to the first opening.”
The 962 Marking Patent is a similar shock absorber to the above discussed Marking Patent which has similar relevant information.
The 895 Marking Patent is a divisional patent to the previously discussed 092 Marking Patent and has the same disclosures as discussed in that patent but has different claims.
The Fox Published Patent Application is an on-the-fly adjustable air spring. This discloses an air spring optionally integrated with a shock absorber or other damping unit, and has an air cylinder closed at one end, and in axially-slidable engagement with a sealing head at the other end.
The Olds Published Patent Application discloses a coil and air suspension system.
The Achnebach Patent talks about a suspension system for a bicycle. It relates to a spring damper system using fluid for bicycles having a first load applying segment, a second load applying segment, at least one spring mechanism, a damping means, and a regulating mechanism that automatically effects a damping behavior of a dampening means based on the tension or load present in at least one spring mechanism.
There is a significant need to provide a lightweight gas spring with an additional volume compensator to significantly improve the gas spring characteristics.